Effects of Helix Angle Variations on Stability of Low Immersion Milling

• Main Authors: B. Moetakef Imani, Kazemi Nasrabadi, Kazemi Sadeghi
• Format: Article
• Language: English
• Published: Iran University of Science & Technology 2008-08-01
• Series: International Journal of Industrial Engineering and Production Research
• Subjects: Low Immersion Milling; Stability; Time Finite Element Analysis; Helix Angle
• Online Access: http://ijiepr.iust.ac.ir/browse.php?a_code=A-10-1-85&slc_lang=en&sid=1

The stability behavior of low immersion helical end milling processes is investigated in this paper. Low radial immersion milling operations involve interrupted cutting which induces chatter vibration under certain cutting conditions. Time Finite Element Analysis (TFEA) is suggested for an approximate solution for delayed differential equations encountered during interrupted milling. An improved TFEA is proposed which includes the effects of helix angle variations on cutting force, cutting time and specific cutting force coefficients. For this purpose, five different cases were distinguished for engagement limits of the cutting edges. It has been observed that an increase in the helix angle improves the stability limit of the process. This is related to the flip bifurcation lobes that start to separate from the main lobes and shape isolated unstable islands. By further increasing the helix angle, unstable islands will vanish .